The vast majority of HIV spread in sub-Saharan Africa occurs through heterosexual contact;when a new patient is discovered it is critically important to find sexual partners who require evaluation for therapy or prevention strategies. Partner notification involves informing the sexual partners of HIV-positive persons that they have been exposed and encouraging them to seek counseling, testing and other prevention and treatment services. Providing counseling, testing, and early care to this very high risk population is crucially important for HIV prevention and mitigation. However, strategies to accomplish these goals in low-income countries have not been well studied and optimized. This project's objective is to increase understanding of HIV partner notification in sub-Saharan Africa by identifying the notification methods most likely to result in partner uptake of HIV counseling and testing and the community-level factors that influence HIV counseling and testing rates. Understanding both the individual and structural factors that influence HIV testing, including the context in which individuals are more likely to respond to partner notification strategies, will suggest future patient-based and community- based interventions for increasing the proportion of the population who are aware of their HIV status. The specific aims of this project are to identify (1)which method of partner notification - patient referral, contract referral, or provider referral ~ results in the highest rate of partner referral and partner HIV-testing uptake;(2) the proportion of previously undiagnosed HIV cases identified among partners for each method of partner notification;and (3) community-level factors influencing HIV counseling and testing uptake. Public Health Relevance: We will conduct a randomized trial of HIV partner notification in an STI clinic in Malawi to determine the rates of counseling, testing and new HIV diagnoses among partners. Community-level factors will be identified through the 2008 Malawi Population and Housing Census, and a multi-level random-effects model will be used to determine their relative association with HIV counseling and testing rates. This research will be the first to provide important local evidence on the most effective method of partner notification in a sub- Saharan African STI clinic patient population.